1. Field of the Invention
The present invention relates to a tilt hinge suitable for use in small-sized office automation equipment such as a laptop-type computer and a notebook-type computer, for connecting a keyboard base, a first member and a display device, a second member, so as to allow to pivot frictionally.
2. Description of the Related Art
A laptop-type computer or a notebook-type computer is composed of a keyboard base and a display device which is openably and closably attached to the keyboard base through tilt hinges. Such a computer is usually folded into two, but when in use, it is structured such that the display device is opened to the keyboard base. Since such types of computers are required to be as thin and compact as possible, tilt hinges are also required to have a small diameter and a high friction function. The following disclosure is well known as the one satisfying such a requirement.
Translated National Publication of Patent Application No. 2000-501149.
The friction hinge described in the above document has a structure that a plurality of washer-shaped clips each having a pair of arms are attached in piles in the axial direction to a holder non-rotatably, and through each pair of the arms a shaft is inserted press-contactedly, causing friction torque between the outer periphery of the shaft and the radial direction of each arm
Since such a friction hinge of a well-known structure described above is aimed at obtaining friction torque by sandwiching a shaft between a pair of arms of a washer-shaped clip, in order to obtain a required value in friction torque with a small-diameter hinge, there arises a disadvantage of requiring a large amount of clips due to smallness in friction area of each clip. Further, when obtaining friction torque of 100 kg-mm with a shaft having a diameter of approximately 7 mm, which is a development requirement of the present invention, a still larger amount of clips become necessary, causing the friction hinge to be longer in size in the axial direction.